Borophagus hilli

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Borophagus hilli[1]
Temporal range: Early Miocene-Early Pliocene, 23.3–4.9 Ma
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Subfamily: Borophaginae
Genus: Borophagus
C. S. Johnston 1939
Type species
Borophagus hilli

Borophagus hilli is an extinct species of the genus Borophagus of the subfamily Borophaginae, a group of canids endemic to North America from the early Miocene epoch (23.3 Mya) through the Pliocene epoch (4.9 Mya).[2]


Borophagus hilli was named by C. S. Johnston in 1939.[3] Though not the most massive borophagine by size or weight, it had a more highly evolved capacity to crunch bone than earlier, larger genera such as Epicyon, which seems to be an evolutionary trend of the group (Turner, 2004). During the Pliocene epoch, Borophagus began being displaced by Canis genera such as Canis edwardii and later by Canis dirus. Early species of Borophagus were placed in the genus Osteoborus until recently, but the genera are now considered synonyms.[1] Borophagus hilli possibly led a hyena-like lifestyle scavenging carcasses of recently dead animals.


Typical features of this genus are a bulging forehead and powerful jaws; it was probably a scavenger.[4] Its crushing premolar teeth and strong jaw muscles would have been used to crack open bone, much like the hyena of the Old World. The adult animal is estimated to have been about 80 cm in length, similar to a coyote, although it was much more powerfully built.[5]


Two fossil specimens of Borophagus hilli were measured by Legendre and Roth for body mass.[6]

  • Specimen 1: 61 kg (130 lb)
  • Specimen 2: 57.7 kg (130 lb)


Borophagus hilli was synonymized subjectively with Borophagus direptor by Kurten and Anderson in 1980 as well as synonymous with Osteoborus crassapineatus, Osteoborus progressus. It was recombined as Borophagus hilli by Xiaoming Wang et al. in 1999.

Fossil distribution[edit]

Borophagus hilli fossil specimens are widespread from east central Florida to southeastern Washington, from Idaho to New Mexico to Texas. Specimens were also found as far south as the southern tip of Baja, Mexico.

See also[edit]


  1. ^ a b Wang, Xiaoming; Richard Tedford; Beryl Taylor (1999-11-17). "Phylogenetic systematics of the Borophaginae" (PDF). Bulletin of the American Museum of Natural History. 243. Archived from the original (PDF) on 2007-03-20. Retrieved 2007-07-08. 
  2. ^ PaleoBiology Database: Borophagus dudleyi, basic info
  3. ^ C. S. Johnston. 1939. Journal of Paleontology
  4. ^ Lambert, David (1985). The Field Guide to Prehistoric Life. New York: Facts on File. p. 163. ISBN 0-8160-1125-7. 
  5. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 220. ISBN 1-84028-152-9. 
  6. ^ S. Legendre and C. Roth. 1988. Correlation of carnassial tooth size and body weight in recent carnivores (Mammalia). Historical Biology: p. 85-98

Further reading[edit]